Although, the analysis of data about student achievement is time-consuming, it is essential in building the case that PLCs are powerful types of reform and with the current demands that schools collect and analyze evidence of student achievement; this analysis is less difficult than it once was. Many teachers and university collaborators note that achievement tests assess a narrow range of learning and may fail to capture the breadth of impact of a PLC. While we would not argue with the validity of this observation, it cannot be used as a rationale for failing to collect evidence of the impact of this work on student achievement.